A current which flows outside the normal conductive paths. This current may be much higher than the normal operating current
Short circuit
100
A qualifying term indicating that no delay is purposely introduced in the tripping action of the circuit breaker
Instantaneous trip
100
A qualifying term indicating that there is purposely introduced a delay in the tripping action of the circuit breaker which delay decreases as the magnitiude of the current increases
Inverse time
100
The circuit of a control apparatus or system that carries the electric signals directing the performance of the controller but does not carry the main power current
Control circuit
100
The steady state current taken from the line with the rotor locked and with rated voltage applied to the motor
Locked rotor current
200
In order to be classified as a continuous load, electrical equipment must be operated for at least what amount of time?
Three hours
200
A continuous load supplied by a branch circuit should not exceed a rating of what percent of the rating of the circuit?
80%
200
A 40 ampere circuit breaker should supply no more than how many amperes to a continuous load?
40 x .80 = 32 amperes
200
Derating of conductor amapacity begins when the number of current carrying conductors in a raceway or cable exceeds what?
Three
200
A unit of equipment which is so constructed that dust will not enter the enclosing case under specified test conditions is classified as what?
dust tight
300
What are three situations in which conductor ampacity must be derated?
Continuous load
Exceed 3 conductors in a raceway or cable
Greater ambient temperature
300
What can an electrician determine about a conductor if he knows the AWG of the conductor?
Allowable current-carrying capacity
300
Unless otherwise specified, when reference is made to conductors in the NEC, what type of material is assumed?
Copper
300
How deep should ground rods be driven?
8 feet
300
What is the minimum diameter required for pipes or conduit used as grounding electrodes?
3/4 inch
400
What is the minimum diameter required for iron or steel rods used as grounding electrodes?
5/8 inch
400
What is the minimum diameter required for nonferrous rods used as grounding electrodes?
1/2 inch
400
When may a circuit breaker be used to protect two or more branch circuits?
Instantaneous trip adjusted to protect the smallest conductor. Double lugs to be used.
400
Does a near zero ohmmeter reading between two equipment frames always indicate proper bonding? Why or why not?
No. It does not indicate the ampacity or impedance.
400
What is the primary purpose for equipment grounding?
Protect the equipment operator
500
When several locations are available for the construction of a ground field, what factor should determine the location chosen?
The area with the lowest ohmic resistance
500
One of the foremost considerations in the construction of a ground field is that all materials used are what with respect to each other?
Compatible
500
How should a connector be marked that is listed for either copper of aluminum conductors?
Does this mean that both copper and aluminum conductors can be connected together in this connector?
A1/Cu
No, unless listed for both together.
500
All components of a ground field should be connected together at a minimum of how many points?
Two
500
What safety precautions should be taken concerning the perimeters of a ground field?